As I said in a post I made a minute ago in another thread, there are a lot of factors that can make a corn comfortable in ones hands. Among these are heat, scent, and pheromones, all combined with natural instinct. As his owner, Tang probably is most often handled by you. He knows your scent, and knows that he is relatively safe with that scent. Corns are territorial by nature and rarely leave an area for one that is unbeknown to them unless they are forced to. They've adapted to this lifestyle over the years and have built a natural instinct to be warry of anything unfamiliar. Your scent has become familiar, and therefore he has no need to be afraid of it. By introducing him to new scents, your putting him in situations he feel he needs to be cautious of. While that sounds like your doing the wrong thing, what your doing is exactly what you should be doing. He needs to know that just because something smells or is new, it doesn't mean he can't feel safe.
You should have him handled by people you know won't freak out if he moves or anything. If you have someone afraid to touch him holding him, they're probably going to be more unpredictable than he is, and he may get hurt if he's dropped suddenly. This type of incident will only prove his instinct right and make him worse. Being handled by people who know what to do if he has random bursts of speed will keep him safe and make him realize that he doesn't have to worry because something is new.
Another thing that might be making him edgy are pheromones. It's been reported numerous times be numerous people (including myself) that snakes will sometimes react based on the sense that whoever is holding them is calm or nervous. Pheromones are scents that we release when we are in a certain state of mind. It's nearly impossible to detect these, but it's been suggested that they are the cause for the 'sixth sense.' Snakes can most likely pick up these pheromones and will act on them.
When I was thinking about buying Kel at an Expo, I asked to hold her for a bit. I was used to snakes and felt comfortable, and she was exactly as you described Tang in your hands- limp and comfortable. I then passed her to my mom, who had some experience with Cali Kings when she was young, but not much else. Kel was a bit flighty in her hands, but was alright overall. She was then passed to my two friend's that I'd brought to the show with me who had never held snakes before. All three began freaking a bit and I quickly grabbed Kel back before all hell broke loose. If someone is calm while holding them, the snake will most likely be calm as well. If someone who is inexperienced with snakes or is afraid of them is holding Tang, he will probably sense that fear, think that there is something to be afraid of, and also start freaking out. (Most often the combined reaction in these cases is not good.
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This is another reason why you need new people to hold him that you know will be calm while doing so. You also need to calm down yourself and trust him, or he will sense your fear as well. Once you have passed this step and has calmed down with new people, then you can start introducing him to people who haven't really been accustomed to holding snakes to get him used to the pheromones.
You just need to be patient during this process. It will probably take a while, but if it's going to happen you need to be able to be the calm one, for both your snake and the people around you. (A new person to snakes, a snake, AND it's owner all freaking out makes for a ten times worse situation.
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Best of luck with your guy.
